Experimental investigations on the failures of woven textile sandwich panels

Abstract

To reveal the deformation, strength, and failure modes of woven textile sandwich composites (WTSCs), test methods suggested by national standards were referenced and discussed to carry out flatwise and edgewise compression experiments, uniaxial stretching experiments, and three-point bending experiments according to the structural characteristics of WTSC. Strength and failure modes of WTSCs in flatwise compression and uniaxial tension were acquired. Anisotropy and size dependency of strength and failure modes of WTSC panels in edgewise compression were revealed. Strength of weft-compressed panels has few variations when the length is smaller than 60 mm and then decreases obviously when the length is over 60 mm, accompanying with the failure modes turning from crushing, fracture to buckling. Progressive crushing and bending fracture are two observed post-failure modes. Two competing shear failure modes and facesheet failure were observed in three-point bending experiments. Shear strength of the woven core of WTSC was deduced by beam flexure. To acquire facesheet failure mode by long beam flexure, the span should be above 36 times the thickness of the panel.

Micromechanical modelling of the compression strength of three-dimensional integrated woven sandwich composites

“…Based on the previous research results [17,18,24,25], compressive load–displacement behavior of an IWSC panel has three distinctive stages as shown in Figure 1. These stages are: (1) elastic region, in which the overall behavior of the sandwich panel is linear up to the first maximum load; (2) after the maximum load, the curve declines dramatically as a result of pile buckling and a plateau behavior occurs in which the rate of force at this stage is almost constant; and (3) densification stage where the load increases rapidly as a result of compaction of tilted piles.…”

“…Moreover, F k and M k are also the local force and local moment in the kth subelement. Thus, stress components of sub-elements in the local coordinate system are calculated by equations (25)…”

Effect of Structural Differences on the Mechanical Properties of 3D Integrated Woven Spacer Sandwich Composites

“…At present, there is no unified test standard for testing the flat compression performance of glass fiber 3D spacer fabric composites in the industry. In this study, GB/T 1453-2005 “Sandwich structure or core flat compression performance test method” was selected based on the material characteristics and experimental equipment [ 17 ]. According to the standard, the test specimens were cut to a size of 60 × 60 mm.…”

A parametric investigation into the flexural properties of singly curved composites reinforced with 3D-integrated woven fabrics

“…Furthermore, another study concluded that edgewise compressive and impact properties proposed a significant improvement compared to non-thickened face sheets [21]. Hu et al [22] carried out experimental investigation on the failures of 3DIWF composites. They reported that to attain face-sheet failure mode by long beam flexure, the span must be higher than 36 times of composite's thickness [22].…”

“…Hu et al. [22] carried out experimental investigation on the failures of 3DIWF composites. They reported that to attain face-sheet failure mode by long beam flexure, the span must be higher than 36 times of composite's thickness [22].…”